Safflower polysaccharide induces cervical cancer cell apoptosis via inhibition of the PI3K/Akt pathway

Safflower polysaccharide (SPS) is a major active component of Carthamus tinctorius L. Previous reports have demonstrated that SPS shows cytotoxic activity against various types of cancer cells; however, its anti-cervical cancer effect remains unclear. Therefore, we explored the effect of SPS treatment of a cervical cancer cell line (HeLa). SPS significantly inhibited cell proliferation and increased the rate of cell apoptosis as determined by TdT-mediated dUTP nick-end labeling assay, Hoechst 33342 staining, and double staining with annexin V-fluorescein isothiocyante/propidium iodide. Furthermore, western blot and real-time polymerase chain reaction revealed that SPS down-regulated mammalian target of rapamycin and protein kinase B and up-regulated Bcl-2-associated death promoter. These results suggest that SPS-induced apoptosis may occur through down-regulation of the phosphatidylinositol-3-kinase/AKT pathway. Collectively, these findings implicate SPS as a candidate for the development of anti-cervical cancer drugs.